Here's an embedded video on using PreziFly to create a player file for your Prezi, including the addition of background narration and music. Note the icon in the lower right to make the video fullscreen if you like. If you prefer, you can directly download this MP4 video from here to play it on your PC or iPad.

This tutorial was made before the use of on-screen buttons by PreziFly was eliminated in version 1.2, but this does not affect how you interact with the program. All other features are up-to-date. The free Audacity sound recorder and editor used in this video can be downloaded from here.

A tutorial on using Camtasia screencasting software to record your Prezi while PreziFly is playing it and convert it to a stand-alone MP4 video, including background narration and music, can be found here. In fact, the video on this page, which includes a Prezi as it is being played by PreziFly, was captured with Camtasia.